Underreamer.



F. W. BITTER, JR. UNDERBEAMER.

APPLICATION FILED JUNE 22, 1998.

926,608, Patented June 29, 1909.

2 SHEETS-SHEET 1.

62 i l, n I 4 i i ii in 3 I l J) F. W. BITTER, Jn. UNDEBREAMBR.

APPLICATION PILED JUNE 22, 1908.

Patented June 29, 1909.

2 SHEETS-SHEET 2.

UNITED STATESEEQTENT OFFICE.

FREDERIG W. BITTER, JR, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO OIL WELL SUPPLY COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF PENN- SYLVAN IA.

UNDERRE AMER.

Specification of Letters Patent.

Patented June 29, 1909.

To all whom it may concern:

Be it known that I, FREDERIC WV. BITTER, J r., a citizen of the United States, residing at Washington city, in the District of Columbia, have invented certain new and useful Improvements in Underreamers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to the construction of that class of devices commonly termed underrcamers having for their purpose the enlargement of the diameter of Artesian or like wells where casing is required and the drilling is done through the casing. In this class of devices, it is essential that the reaming bits be collapsible and expansible in order that the tool may be inserted and withdrawn through the casing, and it is also desirable that the combination of stock and bits should be such that the force of the blow is transmitted to the'stoek on lines substantially parallel to its axis, that any tendency of the bits to spread beyond the normal be restrained or counteracted, and that solid abutments on the stock for the bits be provided. To eileet these several objects I combine with a stock having abutments and a distance-blocklocated intermediate of said abutments a bit support, bits slidingly supported so as to be laterally and bodily movable on said bit support, said bits being slidably connected with the stock so as to be limited as to their lateral movement, and resilient means interposed between the bits and supported upon the dis tance-block whereby the bits are normally held in a spread position and in contact with thev abutments of the stock.

A second feature of my invention embraces the combination with a stock having abutments and a distance-block, of a bit support, sliding bits movable bodily upon the bit su port, and a spring located between the bits and supported upon the distance block, of means for maintaining the relatlon of the spring to the distance-blockand the bit support.

A third feature of my invention embraces the combination with a stock having abutments and a distance block, of a bit support, sliding bits movable'bodily u on the bit support, and a spring located etween the .eral projections sliding bits and supported on the distanceblock, of means for preventing the displace ment of the bit support.

There are other, minor, features of invention, embracing particular combinations and features of elemental construction, all as will hereinafter more fully appear.

In the drawings chosen for the purpose of illustrating my invention, the scope whereof 'is pointed out in the claims, Figure 1 is a view partly in section and partly in elevation, of the lower end of the stock and the bits, of an underreamer embodying my invention. Fig. 2 is a view in elevation of the lower end of the stock and bits of an underreainer embodying my invention. Fig. 3 is a transverse section thereof taken on the line 33, Fig. 2. Fig. 4 is an elevation of the lower end of the stock and bits shown, at right angles to the view in Fig. 2. Fig. 5 a vertical central section of the lower end of a stock and bits constituting a modification of the underreamer shown in Figs. 1 to 4 inclusive. Fig. 6 is a view in elevation of the lower end of the stock and bits of the modified form of underreamcr shown in Fig. 5. Fig. 7 is a similar view to Fig. 6 taken at right angles thereto, and Fig. 8 is a cross sectional view of the modified form of underreamer taken on line 88, Fig. 5.

Like symbols refer to like parts wherever they occur.

I will now roceed to describe my invention more lul y so that others skilled in the art to which it appertains may apply the same.

In the drawings, A indicates the stock, B, B the bits, and O the bit support of an underreamer.

The stock A is provided at its opposite sides with bit recesses a, a for the reception of the tangs b, b of the bits B, B. These bit recesses a, a are closed above by flatwalls or abutments (1/, a against which the flat upper ends I) of the bit tangs abut when the bits are expanded or in their normal operative position. On either side of the said recesses a, a at the lower end of stock A are other flat abutments a a against which flat shoulders b 6 on either side of the tangs b of the bits also abut when the bits are in operative position. The lateral walls of the bit-recesses a, a are channeled longitudinally of the stock to form w: s a for the reception of latb on the bit tangs b, and

be capable of rocking and of moving said channels have an inward and upward inclination, or narrow from below upward to cause and maintain the expansion of the bits when in their operative or normal position.

At the lower end of the stock A and located intermediate of the abutments a a is a distance-block D with which the inner faces of the bits B, B engage, and which serves to maintain the bits expanded when the bits are in their highest position or fully seated on the abutments of the stock.

The stock A may have a, central bore a which extends from the upper end thereof down into the distance-block D forming on the upper face of said distance-block a cup or chamber, (1 for confining the compression spring E, which cup or chamber (11 is slotted vertically as at (Z to ermit of the transverse passage and vertical movement of the bitsupport 0.

The bits B are rovided with tangs I) the upper ends I) of w 1ich are flat to engage the flat abutments a of the stock. Lower down, the bits have flat shoulders 6 b to engage the flat abutments a a at the lower end of the stock A. Projecting laterally from the tangs b are the ribs or projections 6 b" which enter the channels or ways a in the lateral walls of the bit recesses a, a, and this construction permits of a longitudinal sliding movement of the bits with some lateral play of the bits bodily on the bit support C, yet so confines the bits to the stock that no abnormal s reading of the bits can occur. It will thus be seen that the sliding connection between the stock and bits in Figs. 1 to 4 of the drawings is in the character of a dove-tail connection which permits of some bodily lateral movement of the bits. The tangs of the bits B are also provided with slots 6 by means of which they are movably supported on a cross-bar or yoke C, and are recessed on their inner faces, as at b to accommodate or include the distance-block, when the bits are drawn down to their lowest position, or collapsed, as indicated in dotted lines, Figs. 1 and 2 of the drawings. The formation of the recesses of the bits and the undersurface of the distance-block D should be of such a character as will facilitate the disengagement of the bits from the distance-block under the lifting force of compression spring E.

0 indicates a bit support of such proportions as will pass through the elongated slot (1 of the spring cup' (1 and on which the bits B, B are suspended, or supported, sobas 13o odi to and from each other. This bit-suppodt may be of any desired form, but in the preferred form shown in Figs. 1, 3 and 4 of the drawings, it is in the form of a narrow bar having'a depression 0 upon its lower edge, and centrally located, for the reception of a disk 0 which rests upon the compression spring E within the cup or chamber (1, and

this prevents any endwise displacement of the support C.

In the modified construction shown in Figs. 5 to 8 inclusive, of the drawings, in lieu of utilizing the channels or ways a and lateral projections b for forming the sliding connection between the stock and bits, the stock A is provided with a socket S having a slight inward taper for the reception and guidance of the upper ends of the tangs I) of the bits, and this socket has a flat bottom so as to form flat abutments for the upper ends of the tangs b of bits B. The shoulders of the bit are upwardly and inwardly inclined as at s to engage abutments of like inclination on the lower end of the stock A. It will be noted that the coaction of the socket S and the upwardly and inwardly inclined abutments at the lower end of the stock, with the upper and confined ends of the tangs b and the inclined shoulders s of the bits in Figs. 5 to 8 of the drawing, is in eflect thesame as the coaction of the channels a of the stock and the lateral ribs 17 of the bit tangs, in Figs. 1 to 4 of the drawings, that is to say, the coaction of the combining elements in both instances confines the bits to the stock while permitting the restricted bodily lateral movement of the bits required for the expansion and collapse of the bits, and at the same time insures the solid abutment of the bits on the stock when the bits are in the normal or operative position as shown in the full lines of the drawings.

In the modified construction shown in Figs. 5 to 8 of the drawings, in lieu of the cup or 0 block D for confining spring E and maintaining the relation of the s ring to the distance block and bit support there may be employed a guide rod R inserted from below through an opening in the distance-block D and fastened thereto by a pin r or in other suitable manner, its upper end entering a .recess ,r in the bottom of socket S. This rod passes through the compression s ring E and also through an opening in the it support C, and thus serves effectively to confine the spring E and prevent any endwise movement or displacement of the bit support C.

hamber (Z on the upper face of distance- In assembling the elements of the under- Q reamer when the preferred construction of the general character shown in Figs. 1 to 4 of the drawing is adopted, the compression spring E is passed down through central bore a of the stock to its position in cup 0', and the disk 0 dropped into position on the upper end of said spring. Next, the tangs b of the bits are passed up into the bit recesses in the lower end of the stock with the lateral ribs or projections b of the bit tangs in the ways a? of the stock the stock and'bits' meet, as indicated in the full lines of the drawings, after which the spring E is placed under compression, which can be readily done through the bore a of the stock. Finally, the bit-support C is passed transversely through the slots 1) in the tangs b of the bits and through the elongated slot d n the walls of the spring chamber d, whereupon, upon the removal of pres sure from spring E the disk 0 will seat itself in the recess 0 on the lower edge of the bit support C and confine the bit support against endwise dis. lacement.

In case 0 the modified construction shown in Figs. 5 to 8 of the drawing, in assembling the parts, one bit B and the bit support (I are first placed in position as indicated in the full lines of the drawing after which the compression spring is placed in position between the u per surface of the distance block D and tlie under surface of bit support 0. Next, the bit-support is drawn down by the attached bit until it reaches the position indicated in dotted lines which will bring the bit-support below the mouth of socket S, whereupon the other bit is hung on the bit support and when the pressure is removed from spring E the tangs I), Z) of bot-h bits will be forced up into socket S and at the same time the inclined shoulders s on the bits will engage the inclined abutments on the lower end of the stock A. Finally, the rod R will be passed through the opening in the distance-block D, springs E and bit-support (l and will be secured thereon by the pin 1 or in other suitable manner.

The construction being substantially such as hereinbefore set forth,-when the under reamer is to be introduced through the easing the bits B, B are drawn down until the recesses If on their inner faces are opposite the lower end of the distance-block D when the bits can be forced toward each other into the collapsed position shown in dotted lines. This puts the spring E under compression, in which condition it remains during the passage of the underreamer through the casing, the bits being retained in said position by the walls of the casing. When the bits emerge from the lower end of the casing the pressure on spring E is relaxed whereupon the reaction of the spring forces the bits upward until they are seated solidly upon the abutments of the stock, the distance-block D separating the lower portions of the bits and thereafter maintaining them in their normal or operative osition while the ways a and ribs If in the one instance, and the socket S and the inclined abutments and shoulders s in the other instance counteraet any excessive spreading or lateral movement of the bits.

When withdrawing the underreamer from the casing the projecting outer faces of the tangs b, l) of the bits first encounter the lower end of the casing and the bits are held thereby while the stock A continues to rise, the

compression of the spring E permitting this relative longitudinal movement of the bits and stock until such time as the recesses If on the inner faces of the bits are opposite the under face of the distance-block D, whereupon the bits colla se or assume the position shown in dotted ines, thus permitting the under reamer to be drawn into and through the casing.

One advantage derived from the location of the s )ring on the distance block and between the bits is that the bit stock or mandrel may be materially shortened thus bringing the jars nearer to the bits and rendering the tool more ell'ective. Another advantage is the securing of a more solid bit-stock for the better transmission of the blow and the support of the bits near their cutting faces.

llaving thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In an underreamer, the combination with a bit-stock having laterally disposed abutments at its lower end and a distanceblock intermediate of said abutments, of a bitsui ')port, bits carried by the bit-support and bodily movable thereon, said bits being slidingly connected to the bit-stock so as to have a limited lateral movement and being adapted to engage said abutments near the lower ends of said bits, and a resilient element interposed between the bits and supported on the distance block for holding the bits normally expanded and in contact with the abutments of the bit-stock.

2. In an underreamer, the combination with a bit-stock having laterally disposed abutments at its lower end and a distance.- block intern'icdiate of said abutments, of a bit support, bits sliding-1y connected with the bit-stock and bodily movable on the bit-support, a spring located between the bits and supported on the distance-block for holding the bits normally expanded and in contact near their lower ends with the abutments of the bit-stock, and means connected to the distance block for maintaining the spring in alinemcnt with the distance-block and bitsupport.

3. In an underreamer, the combination with a bit-stock having lateral abutments at its lower end, a distance-block intermediate of said abutments, and an axial bore which terminates at the distance-block and forms a spring chamber the walls of which are slotted transvcisely for the passage of a bit support, of a bit-support, bits slidingly connected with the bit-stock, and a spring located in the bore of the stock between the bits and supported by the distance block for holding the bits normally expanded and in contact near their lower ends 'with the abutments of the bit-stock.

it. In an underreamcr, the combination with a bit-stock having lateral abutments v tact with the abutments of the bit-stock, and

l lower ends of the latter and a distance-block posed between the spring and the bitsupconfined within the axial and a distance-block, said bit-stock provided with an axial bore and a transverse bit-support slot, of a bit-support, bits carried by the it-support and slidingly connected with the bit-stock, a spring located between the bits and supported on the distance-block for hold ing the bits normally expanded and in conmeans within the axial bore of the bit-stock, confined thereby and which engages the bitsupport for preventing the endwise displacement of the bit-support, said means interort.

p 5. In an underreamer, the combination with a bit-stock having an axial bore, lateral abutments, and a transverse slot for the passage of a bit-support, of a bit-support, a disk bore of the bitstock and which engages the bit-su port to prevent its endwise dlsplacement, its carried by the bitsupport and slidingly connected with the bit-stock, and a spring located between the bits and beneath the bitsupport for holding the bits normally expanded and in contact with the abutments of the bit-stock.

6. In an underreamer, the combination with a bit-stock having lateral abutments and an axial bore and provided with a transverse slot for the passage of a bit-support, of a bit-support, having a recess in its edge for the reception of a disk, bits carried by the bit-support, a compression spring located in the bore of the bit-stock between the bits and beneath the bit-support for holding the bits fined in the axial bore of the bit-stock be' tween the s ring and bit-support and which engages in iihe recess of the bitsupport.

7. A bit-stock for underreamers, said bit stock having lateral bit-abutments which are adapted to engage cutting bits near the intermediate of said abutments, and provided with an axial bore which extends down from the upper end of said stock and terminates at the distance-block constituting a spring chamber intermediate of said bitabutments.

8. In an underreamer, the combination with a bit-stock having lateral abutments, a distance-block intermediate of said abutments and an axial bore which extends downward to the distance block forming a spring chamber the walls of which are transversely slotted, of a bit-support, bits loosely carried by said bit-support and slidingly connected to the bit-stock, and a compression spring located between the bits and interposed between the bit-support and distancelock for maintaining the bits normally in expanded position and in engagement near their lower ends with the abutments of the bit-stock.

In testimony whereof I afl ix my signature, in presence of two subscribing witnesses.

FREDERIC W. BITTER, JR. Witnesses:

I G. P. BITTER,

HUGH M. STERLING. 

